Although there is much interest in the study of emotions and memory in childhood, empirical findings have been mixed. One reason for the discrepancies concerns individual differences among children. Specifically, the relations between emotion and memory may depend on characteristics in children that affect both their emotional reactions to and memory for their experiences. The purpose of the proposed research is, first, to determine whether individual differences in children's physiological reactivity, that is, children's ability to regulate their physiological reactions to stress, influence their memory for negative and positive emotional information, and second, to determine the processes by which reactivity influences children's memory. One hundred twenty five-year-olds will take part in a protocol composed of challenging tasks. During the protocol, children's physiological responses will be monitored to identify reactive and nonreactive children. Reactive children have difficulty regulating their responses. They tend to exhibit exaggerated, prolonged physiological reactions to stress, whereas nonreactive children are better able to regulate their reactions. Two weeks after the protocol, children's memory for negative and positive emotional information (e.g., emotionally evocative video clips) will be tested. Within the reactive and nonreactive groups, half of the children will be questioned by a friendly, supportive interviewer, and half will be questioned by a cold, nonsupportive interviewer. By manipulating interviewer-provided social support, it will be possible to determine if encoding failures or some other factor (e.g., retrieval difficulties) underlie associations between emotion and memory in some children (i.e., those considered physiologically reactive). Broadly, the study's results will advance theory concerning how emotions affect memory in childhood. The results will also provide practical information about children's ability to recount personal, emotional experiences. By identifying the mechanisms that underlie children's memory for emotional information, it will be possible to determine whether or not and how best to intervene and improve their memory abilities. This knowledge will benefit educators, clinicians, legal professionals, and others charged with the responsibility of obtaining accurate and complete accounts from children across a variety of contexts.